| 摘要 |
PURPOSE:To make the frequency stable against the humidity change, by connecting a capacitor in parallel with a crystal oscillator and forming the capacitor in an integrated circuit. CONSTITUTION:A capacitor 210 is connected in parallel with the crystal oscillator 204. The capacitor 210 is formed in a semiconductor integrated circuit. Thus, the capacitor 210 is hardly changed against the humidity in comparison with a fixed capacitor placed at the outside of the semiconductor. When the humidity around the crystal oscillator 204 is increased, a floating capacitance between the lead pattern, the substrate and ground is changed. As a result, the capacitance between the terminals of the crystal oscillator is changed. Since the capacitance of the capacitor 210 is not so much changed, the effect of the floating capacitance on the frequency can be reduced relatively. |
